JPS6223748B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to certain benzamide derivatives and herbicides containing the benzamide derivatives. The present inventors investigated the herbicidal activity of various compounds and discovered the unique action of a specific benzamide derivative, leading to the completion of the present invention. That is, the first invention of the present invention is a benzamide derivative shown below, and the second invention is
This is a herbicide containing the benzamide derivative as an active ingredient. general formula (R in the formula is an alkylsulfonyloxy group,
Indicates a halo-substituted alkylsulfonyloxy group, an alkyl-substituted phenylsulfonyloxy group, and an alkylsulfamoyloxy group. ) Next, typical benzamide derivatives according to the present invention are shown in the table. Note that for the structural formulas in the table, only substituents are shown for convenience.

[Table] The compounds of the present invention are 4-hydroxy-N-
Potassium salt of (2,3-dichlorophenyl)-benzamide and various sulfonyl chlorides and sulfamoyl chlorides are mixed in acetone, tetrahydrofuran, dioxane, dimethyl chloride, etc. in the presence or absence of basic salts such as potassium carbonate. By reacting in an organic solvent such as formamide, dimethylacetamide, dimethyl sulfoxide, etc., it can be easily obtained with high yield and high purity. Next, a typical synthesis example will be shown. Synthesis Example 1 0.7 g of potassium salt of 4-hydroxy-N-(2,3-dichlorophenyl)-benzamide and 4 ml of acetone were placed in a 50 ml four-necked flask, and while stirring at room temperature, 0.3 g of methanesulfonyl chloride was added into the flask. ml and 4 ml of acetone were added dropwise little by little. After the dropwise addition was completed, the reaction solution was heated and stirred for 6 hours in such a state that the acetone was refluxed to complete the reaction. After the reaction is complete, the acetone in the reaction solution is removed by evaporation using a rotary evaporator, and the residue is dissolved in approximately 200 ml of ethyl acetate.
dissolved in Add this ethyl acetate solution to 100 ml of 3% sodium hydroxide aqueous solution while adding a little ice.
×3 times and 100 ml of water ×3 times, then dehydrated with anhydrous sodium sulfate, and ethyl acetate was removed by evaporation to produce the target product, 4-methylsulfonyloxy-N-(2,3-dichlorophenyl). ―
0.68 g of benzamide was obtained. Yield 86.3%, melting point
The temperature was 148-151℃. Synthesis Example 2 While stirring 0.7 g of potassium salt of 4-hydroxy-N-(2,3-dichlorophenyl)-benzamide, 0.31 g of potassium carbonate, and 4 ml of tetrahydrofuran at room temperature, add 0.5 ml of dimethylsulfamoyl chloride and 0.5 ml of dimethylsulfamoyl chloride. 2 ml of tetrahydrofuran
Add the solution dropwise. After completing the dropwise addition, heat the reaction solution to reflux the tetrahydrofuran.
The reaction was completed by heating and stirring for about 8 hours. After the reaction was completed, tetrahydrofuran in the reaction solution was removed by evaporation, and the residue was dissolved in about 200 ml of benzene.
After washing this benzene solution with 100 ml of 3% aqueous sodium hydroxide solution three times and 100 ml of water three times,
After dehydration and filtration over anhydrous sodium sulfate, the solvent was removed by evaporation. By recrystallizing this residue from benzene, the target product 4-dimethylsulfamoyloxy-N-(2,3-dichlorophenyl) was obtained.
-0.67g of benzamide was obtained. Yield 78.7%, melting point
The temperature was 151-153℃. Synthesis Example 3 While stirring a mixed suspension of 0.5 g of potassium salt of 4-hydroxy-N-(2,3-dichlorophenyl)-benzamide, 0.22 g of potassium carbonate, and 4 ml of acetone at room temperature, p-toluene was added into the suspension. A mixture of 0.45 g of sulfonyl chloride and 4 ml of acetone was added. Thereafter, the mixture was stirred at room temperature for about 7 hours to complete the reaction. After the reaction was completed, the reaction solution was evaporated to dryness using a rotary evaporator. After adding 200 ml of ethyl acetate to the evaporation residue and dissolving it well, the ethyl acetate solution was added to the separatory funnel for 3 minutes.
% NaOH 100 ml x 5 times, then tap water 100 ml x 3 times, then the ethyl acetate layer was dehydrated with anhydrous sodium sulfate, the liquid was evaporated to dryness, and the obtained evaporation residue was diluted with benzene. Recrystallization yielded 0.49 g of the target product, 4-(P-toluenesulfonyloxy)-N-(2,5-cyclophenyl)-benzamide. Yield 71.9%, melting point
The temperature was 168.5-170.5℃. The herbicide of the present invention is obtained by mixing the active ingredient compound with various carriers and formulating the mixture in the form of a wettable powder, emulsion, powder, granule, or the like. Among the carriers, liquid carriers include ordinary organic solvents, solid carriers include
Ordinary mineral fines are used. In addition, a surfactant can be added to impart emulsifying properties, dispersibility, spreading properties, etc. during preparation of the formulation. Furthermore, it can also be used in combination with agricultural chemicals such as fertilizers, herbicides, insecticides, and fungicides. The herbicide of the present invention mainly suppresses the germination and growth of weeds, and has an excellent control effect on weeds of the grass family, such as field weed, slime grass, and azagaya, as well as grass weeds of the water mallow family, especially in soil treatment under flooded conditions. It is a highly selective herbicide that not only exhibits a growth-suppressing effect on broad-leaved weeds such as chickweed and weed grass, but also causes almost no damage to transplanted paddy rice. Next, the herbicide of the present invention will be explained using formulation examples and test examples. Formulation example 1 (hydrating powder) Zeeklite 97 parts by weight Neopellex powder 1.5 parts by weight (trade name: manufactured by Kao Atlas Co., Ltd.) Solpol 800A 1.5 parts by weight (trade name: manufactured by Toho Chemical Industry Co., Ltd.) The above The components were uniformly ground and mixed to obtain a carrier for a wettable powder. Carrier 90 for wettable powders obtained as above
parts by weight, and 4-methylsulfonyloxy-N-
(2,3-dichlorophenyl)-benzamide 10
Parts by weight were uniformly ground and mixed to obtain a wettable powder. Formulation Example 2 (Emulsion) 4-ethylsulfonyloxy-N-(2,3-dichlorophenyl)-benzamide 10 parts by weight Cyclohexanone 40 parts by weight Xylene 40 parts by weight Solpol 800A 10 parts by weight The above components were uniformly mixed and dissolved. An emulsion was obtained. Test Example A porcelain pot measuring 1/15,500 are was filled with paddy soil, and seeds of wild grass, slime grass, azalea, and japonica were uniformly sown on the surface layer, and the pot was submerged in water to a depth of 2 cm. Furthermore, two paddy rice seedlings (variety: Nipponbare) at the second leaf stage were transplanted. Then, when weeds germinate,
A diluted wettable powder solution of each test compound was dropped into water in a predetermined amount of each drug. On the 20th day after the chemical treatment, the herbicidal efficacy against wild grass, slime grass, Japanese azalea, and Japanese grasshopper, as well as the response of transplanted paddy rice to the chemical, were observed and investigated according to the following criteria. Weeding effect Plant damage to transplanted paddy rice 0: No effect (no effect) 1: Harmless 1: Slight ±: Slight damage 2: Small +: Slight damage 3: Medium 〓: Medium damage 4: Large 〓: Large damage 5: Extremely large (100%) Weeding) The results are shown in the table below.

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Claims (1)

[Claims] 1. General formula (R in the formula is an alkylsulfonyloxy group,
Indicates a halo-substituted alkylsulfonyloxy group, an alkyl-substituted phenylsulfonyloxy group, and an alkylsulfamoyloxy group. ) A benzamide derivative represented by 2 General formula (R in the formula is an alkylsulfonyloxy group,
Indicates a halo-substituted alkylsulfonyloxy group, an alkyl-substituted phenylsulfonyloxy group, and an alkylsulfamoyloxy group. ) A herbicide containing a benzamide derivative represented by: